Method and apparatus for constructing a set-top box to protect cryptographic capabilities

Abstract

A construction arrangement for a small set-top box to protect cryptographic capabilities and prevent a digital program in clear from being able to be tapped as required by Digital Rights Management protocols. A first layer of sheet metal capable of blocking X-rays, is formed as a shallow pan to hold a set of printed circuit boards. A second layer has a thin epoxy based printed circuit material. A third layer has a printed circuit board with integrated components placed on top of the second layer. A fourth layer has a three layer thin printed circuit board with a first and second metallic layer and holes for large components, such as electrolytic capacitors. A black liquid thermosetting epoxy fills the interstices between the sheet metal layer and the second layer, and between the second layer and the third layer, and between the third layer and the fourth layer, thereby preventing access to exposed circuit trace carrying digital signals in the clear. A connection from the first metallic layer of the fourth printed circuit material layer to a sending circuit and a connection from the second metallic layer so that a short between these two layers sets off an indicator circuit that an attempt is made to enter the protected area.

Description

RELATED PATENT APPLICATIONS [0001] This patent stems from a divisional application of U.S. patent application Ser. No. 10 / 328,868, and filing date of Dec. 23, 2002, entitled METHOD AND APPARATUS FOR VIEWER CONTROL OF DIGITAL TV PROGRAM START TIME, with inventors PAUL BARAN, XU DUAN LIN, JOHN PICKENS and MICHAEL FIELD, and from a provisional patent application having Ser. No. 60 / 382,174, and filing date of May 21, 2002, entitled METHOD AND APPARATUS FOR VIEWER CONTROL OF DIGITAL TV PROGRAM START TIME, with inventors PAUL BARAN, XU DUAN LIN, JOHN PICKENS and MICHAEL FIELD, and a provisional patent application having Ser. No. 60 / 344,283, and filing date of Dec. 27, 2001, entitled MINI STE TOP BOX, with inventor PAUL BARAN. The benefit of the earlier filing dates of the prior applications is claimed for common subject matter.BACKGROUND OF THE INVENTION [0002] This invention relates to digital cable television, and more particularly to placing viewer in command of when the viewer chooses...

AI Technical Summary

Benefits of technology

[0011] According to the present invention, as embodied and broadly described herein, a method and apparatus for viewer control of digital TV program start time is provided. The apparatus includes an input unit, a storage unit with a disk array, a gigaQAM unit, a controller, and a conditional access unit. The input unit receives digital channels from multiple constant bit rate and variable bit rate sources, e.g. HITS, Microwave, Satellite, RF Broadcast, and local video processing sources. The storage unit provides both capture and playout of real time video streams. In addition, files can be stored and played out on demand, i.e. video-on-demand is one application of this feature. The disk array contains both disk controllers and a large number of IDE disk drives. The gigaQAM unit receives MPEG encoded digital channels over a 10 Gigabit Ethernet interface from the storage unit or other source. The gigaQAM unit routes and duplicates each digital channel. Program information is inserted. PCR correction is performed and null frames are inserted. The Controller 800 manages the switching set up of information pathways from the Input unit 400, Storage unit 300 and gigaQAM unit 200. It constructs valid Program Specific Information (PSI) and System Information (SI) for the output multiplexes created at the gigaQAM unit. The controller manages the switching set up of information pathways from the input unit, Storage unit and gigaQAM unit. The controller constructs valid Program Specific Information (PSI) and System Information (SI) for the output multiplexes created at the gigaQAM unit. The conditional access unit enables the operator to authorize subscriber access to digital program streams. The conditional access unit offers a cryptographically strong conditional access solution augmented with physical mechanisms to enhance security.

[0012] A video server divides the input video-streams up as they each separately enter the system and then sends the divided video-streams to a server that has a simple switch as it's first component. Each divided video stream is identified with a separate Ethernet address. A switch routes the appropriate piece of the video stream to the appropriate disk drive. When replaying the video stream the disk drive controllers co-operate together to send their portions of the video stream at the appropriate time back out through the switch. In this way the problem of a single bottleneck of a CPU and RAM is eliminated to provide a video-server in which many CPU's are working in parallel to produce a much larger number of video streams.

Problems solved by technology

The digital TV posed a competitive threat to the cable operators.

A pacing factor in the inevitable evolution of cable to an all-digital environment is the cost of the set-top unit.

Current set-top units are expensive, especially in the United States.

With a set-top unit required by each TV set, that displays digital signals, the cable industry faces an overly expensive investment unless an alternative is provided.

Digital processing and storage are continuing historic price declines.

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